Attachment nuts that incorporate an anti-loosening feature or anti-back up feature, generally referred to as lock nuts or torque nuts, are well known in the art. These attachment nuts often have threads designed to deform as the nut is tightened down with a predetermined amount of torque, preventing it from loosening thereafter. A typical application for such fasteners in the automotive industry is to fix a wheel bearing assembly to the end of a shaft. While they work well mechanically, the common drawback to such fasteners is cost. Besides being much more expensive initially than a conventionally threaded nut, they are, by definition, not reusable, since they deform at final tightening. It would be desirable, if possible, to provide a workable, economical anti-loosening capability for a conventionally threaded, reusable nut.